Lemon, you are right exams are not the ideal way to determine who is best or better or who stands where. But since a system of education has to work and some form of evaluating the students has to be derived. So different formats of exams are being experimented from time to time to make it as much as possible level playing field. But do not bother much about these exams you have at school or university. The real exam starts after that :)
So even if you have not scored well in exams you can still succeed in life and vice versa is also possible. Exams are just the basic parameter to segrargate good from not so good but things can change later and at each stage of your life.
So bitter truth is that for now you have to give exams if you want to study at school or university :)
All the best!
If you do not want , you do not need to take exam. However, you would pass the chance sometimes.